import MapKit
import CoreLocation

class CheckoutLocationManager: NSObject,
    ObservableObject, CLLocationManagerDelegate {

    private let manager = CLLocationManager()
    @Published var location: CLLocation?
    @Published var placemark: CLPlacemark?
    @Published var deliveryETA: TimeInterval?

    private let restaurantCoord = CLLocationCoordinate2D(
        latitude: 37.7749, longitude: -122.4194)

    override init() {
        super.init()
        manager.delegate = self
        manager.requestWhenInUseAuthorization()
        manager.startUpdatingLocation()
    }

    func locationManager(_ manager: CLLocationManager,
        didUpdateLocations locations: [CLLocation]) {
        guard let location = locations.first else { return }
        self.location = location

        // Reverse geocode: turn lat/lng into a street address
        CLGeocoder().reverseGeocodeLocation(location) {
            placemarks, _ in
            self.placemark = placemarks?.first
        }

        // Estimate driving time from restaurant to user
        let request = MKDirections.Request()
        request.source = MKMapItem(
            placemark: MKPlacemark(coordinate: restaurantCoord))
        request.destination = MKMapItem(
            placemark: MKPlacemark(coordinate: location.coordinate))
        request.transportType = .automobile

        MKDirections(request: request).calculate {
            response, _ in
            if let route = response?.routes.first {
                DispatchQueue.main.async {
                    self.deliveryETA = route.expectedTravelTime
                }
            }
        }

        // Distance-based delivery fee
        let dest = CLLocation(latitude: location.coordinate.latitude,
            longitude: location.coordinate.longitude)
        let rest = CLLocation(latitude: restaurantCoord.latitude,
            longitude: restaurantCoord.longitude)
        let meters = dest.distance(from: rest)
        let miles = meters / 1609.34
        self.deliveryFee = miles > 5
            ? 7.99 : miles > 2 ? 3.99 : 0
    }
}